Pattl bartsch



' the wood, the steps Reissued Feb. 14, 1928.

UNITED STATES l PATENT OFFICE.

PAUL BARTSCH, OF WASHINGTON, DISTRICT OF COLUMBIA.

METHOD or woo]: PROTECTION.-

lfo Drawing. Original No. 1,374,806 dated April 12, 1921, Serial No. 419,063 filed tlctober 23, 1920.

' Application for reissue filed July 15, 1927. Serial No. 296,122.

This invention relates to a method of treating woodwhereby it is protected against shipworms, borers, dry rot and fungus deca a The various methods employed heretofore for protecting wood subject to the. action of water against shipworms, borers, dry rot and fungus decay have been ineflicicnt.

-Where creosote is used asa protective medium it will leach out in a varying length v of time, depending upon the temperature-of the water, leaving the wood exposed to theravages of the destruct ve organisms sooner or later. Poisons supplied to the fibers of the wood by existing methods will not penetrate far enough to insure eomplete'protection and after the thin outer shell of the wood has been removed, therest can easily be destro ed by the invading organisms.

One 0 the objects of the present invention is to completely oison all the tissuesof IF the process being such as to cause thepoisons to permeateall the cells, fibers, vessels, ducts and pores, as well. as the intercellular spaces in the wood, thereby'rendering the wood immune against the attack of'dest'ructive organisms.

Another object is to seal up all the polsons with which 'the tissues lltLYGbGCIlflll'lpregnated, thereby preventing them from leaching out' when the treated wood is subjected to rain or submerged in fresh or salt water.

Another object is to so treat the wood that every newly-eut surface will expose a poison which will promptly kill borers ingesting bits of the wood, with the result that shipworins and other-destructive animals will not have a chance to burrow into the wood because the.

microscopic larval form or adult will bekilled'long before it will have buried itself 2 within the tissues of thewood.

A furthe-r object is to treat the wood as to completely extract the water and resin and the sealing medium.

irom'the' cells, fibers, vessels, ducts andpores, asp wjellas the intercellular spaces in.

the ivoodi-tafid' replace them by thepoisons With the foregoing'and other objects view, which will appear as the descniption proceeds, the invention consists in first completely deresinizing the wood with a resin solvent such as xylol or turpentine or any other chemical used f or such pur oses until complete deresiniaation has to en place.

This step of the method leaves the wood in a completely deresinized condition with the cells, fibers, vessels, ducts and, pores, as well as the intercellular spaces in the wood, saturated with the resin solvent. This solvent is then replaced by alcohol, or any otherwater miscible solution that can be employed i'or in .water in which the above solvent is removed. (l/Vherc non-resinous woods are treated the d eresinizing process may ,be elimi'natecl' and the wood nlay besubiccted at once to the poisoning process which fo'llows.) The deresinized wood'is next subected to saturated solutions of arsenic and copper compounds which will, consequently,

fill the cells, fibers, vessels, ducts and pores, aswell as the intercellular spaces in the wood. "lhe wood is next saturated with a.

precipitant, such as alcohol, which will pre- .cipitatethe poisons withinthe tissues of the wood.' This precipitation step is also a part of the next feature of our treatment, that is, complete dehydration, which is essential to secure complete penetration of the parafliu. ing the liquid in the wood with a paraflin solyent such asturpentine. 'Finallythe wood 18 immersedin paraflin heated to ,above the melting point and which has been poisoned with arsenic and copper salts. The turpensuch purposm The wood is next immersed The next step consists in'replac-v I tine in the wood will be displaced by the y paratfin'which, in turn, will completely impregnate the wood and seal the poisons.

thereby protecting them from the actionof water and preventing leaching.

It will be apparent, from 'the foregoing,

that the wood treated in the manner set forth will contain encapsuledpoison in every cell, fiber, vessel duct and pore, as well hs in the intercellular spaces in the wood, throughout thethickness of the-wood. The poisoned. parafiin, while toxic; itself, will seal up all the poisons with which the tissues have been impregnated. The. arsenic compounds will poison the animal preying upon the wood;,in the case of dry rot or fungus, the copper salts-will'have anequally toxic effect upon those organisms, should they attempt to penetrate the treated wood..

- What I claim is:' x

1. The method of protecting wood comprising dehydration and saturation of the wood with melted poisoned paraflin.

2. The'method oflprqtecting wood comioo .intercell-ular poisoned parafiin;

prising dehydration and saturation of the,

and copper compoundsf The hereindoseribed method of protecting wood from organisms whioh'consist-s in dehydration of the wood, impregnation of wood with parafiin poisoned with arsenic the "wood with a saturated solution of poison, precipitation of the poison within the cells, fibers pores, ducts, vesselsand inter cvllularspaeesin-the wood, and sealing the minute particles of'prec'ipitated poison within the cells, fibers, pores, ducts, vessels and spaces,

The lei-eindeseribed niethod' of protec ting wood from organisms; Which con'sists'in Y deresinizing the woodwith a resin'solvent,

removin t 1e solvent,'suhjecting the Wood to a saturated solution of poison, dehydratingin the 1 wood with the Wood and precipitating the poison Within the tissues of the Wood, displacing thiede hydrant by a paraffin'solvent, and immersing thei'wood .in melted poisoned paraflin', to completely in'ipregnatethe wood with the paraflin. I v P I 5. The hereindescribed'method of protesting wood from destructive organisms, which consists in deresinizing the wood by means of a solvent, reniovi'ngthe' solvent'and resin; re 'ilaoingthis' with a chemical that will not only replace the resin solvent but will, in turn, be replaced by an aqueous solution of arsenic and copper, then chemically dehy drating the wood to cause precipitation' ,of the poisons, thenreplacing the dehydrantby a paraffin solvent and finally-replacing the paraffin solvent by poisoned parafiin. i

- PAUL BARTSCI-I; 

